With the increasing popularity of wide area networks (WANs), such as the Internet and/or the World Wide Web, network growth and traffic has exploded in recent years. Network users continue to demand faster networks and more access for both businesses and consumers. As network demands continue to increase, existing network infrastructures and technologies are reaching their limits.
An alternative to present day hardwired or fiber network solutions is the use of wireless optical communications. Wireless optical communications utilize point-to-point communications through free-space and therefore do not require the routing of cables or fibers between locations. In a typical free-space optical communications system, a modulated beam of light is directed through free-space from a transmitter at a first location to a receiver at a second location. Data or information is encoded into the beam of light by means of the modulation. Once collected by the receiver, the modulated beam of light is demodulated and corresponding data and information may then be extracted. This scheme enables data and information to be transmitted through free-space from the first location to the second location.
Transmission of optical signals through free space poses many challenges. Notably, optical communications systems operating in free-space are subject to ambient light and interference from other optical communication systems, which can both manifest as a moving baseline that detrimentally affects performance of an optical communications system. As such, there may be a need for optical carriers and modulation schemes (e.g. at the transmitter), and optical detection methods and demodulation schemes (e.g. at the receiver), to compensate for the effects of the interference and ambient light on a signal received at a receiver.